Submission #339213

#	Time	Username	Problem	Language	Result	Execution time	Memory
339213		Kerim	Split the sequence (APIO14_sequence)	C++17	100 / 100	667 ms	83932 KiB

sequence

#include "bits/stdc++.h"
#define MAXN 100009
#define INF 1000000007
#define mp(x,y) make_pair(x,y)
#define all(v) v.begin(),v.end()
#define pb(x) push_back(x)
#define wr cout<<"----------------"<<endl;
#define ppb() pop_back()
#define tr(ii,c) for(__typeof((c).begin()) ii=(c).begin();ii!=(c).end();ii++)
#define ff first
#define ss second
#define my_little_dodge 46
#define debug(x)  cerr<< #x <<" = "<< x<<endl;
using namespace std;

typedef long long ll;
typedef pair<ll,int> PII;
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
ll dp[MAXN],par[MAXN],odp[MAXN];
const int N=202;
int ata[N][MAXN],sz;
vector<ll>m,b;
vector<int>z;
double inter(int l1,int l2){
	return double(b[l2]-b[l1])/double(m[l1]-m[l2]);
}
bool bad(int l1,int l2,int l3){
	return inter(l1,l3)>inter(l1,l2);	
}
void upd(ll x,ll y,int ind){
	if(sz and m[sz-1]==x and b[sz-1]>=y)
		return;
	if(sz and m[sz-1]==x)
		m.ppb(),b.ppb(),z.ppb(),sz--;
	m.pb(x);b.pb(y);z.pb(ind);sz++;
	while(sz>=3 and bad(sz-3,sz-2,sz-1)){
		m.erase(m.end()-2),b.erase(b.end()-2),z.erase(z.end()-2);
		sz--;
	}
}
int pnt=0;
PII tap(ll x){
	umin(pnt,sz-1);
	while(pnt+1<sz and m[pnt]*x+b[pnt]<m[pnt+1]*x+b[pnt+1])
		pnt++;
	return mp(m[pnt]*x+b[pnt],z[pnt]);
}	
int main(){
    //freopen("file.in", "r", stdin);
    int n,k;
    scanf("%d%d",&n,&k);
    for(int i=1;i<=n;i++){
    	int x;scanf("%d",&x);
    	par[i]=par[i-1]+x;
    }	
	for(int h=1;h<=k;h++){
		m.clear();b.clear();z.clear();sz=0;
		for(int i=h+1;i<=n;i++){
			upd(-par[i-1],dp[i-1]-par[i-1]*par[i-1],i-1);
			PII res=tap(-par[i]);
			odp[i]=res.ff;ata[h][i]=res.ss;
		}
		for(int i=h+1;i<=n;i++)dp[i]=odp[i];
	}
	printf("%lld\n",dp[n]);
	vector<int>ans;int who=ata[k][n],rem=k;
	while(who)
		ans.pb(who),who=ata[--rem][who];
	reverse(all(ans));
	tr(it,ans)printf("%d ",*it);
	puts("");
	return 0;
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:52:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   52 |     scanf("%d%d",&n,&k);
      |     ~~~~~^~~~~~~~~~~~~~
sequence.cpp:54:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   54 |      int x;scanf("%d",&x);
      |            ~~~~~^~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 11 / 11
• Subtask 3: 11 / 11
• Subtask 4: 17 / 17
• Subtask 5: 21 / 21
• Subtask 6: 29 / 29